Pneumatic action for player-pianos.



H. MEYER.

PNEUMATIC ACTION FOR PLAYER PIANOS.

APPLICATION msu ocT. 1I. 1914.

l ,27 l, l 93. Patented July 2, 1918.

HARRY MEYER, OF WELLSTON, MISSOURI.

PNEUMATIC ACTION FOR PLAYER-PLANOS.

Application led October 17, 1914.

To all whom t may concern Be it known that I, HARRY MEYER, a citizen of the United States, and a resident of Vellston, in the county of St. Louis and State of Missouri, have invented a new and useful Improvement in Pneumatic Actions for Player-Pianos, of which the following is a specification.

My invention relates to pneumatic actionsfor player pianos or other mechanically played musical instruments, and has for its principal object to make a pneumatic action which will be compact and cheap to manufacture, and in which the different parts are readily accessible and can be easily adjusted or replaced. A further object is to make a compact unit of a small number of pneumatics, preferably twelve, which can be easily attached to another pneumatic action. A further object is to improve and simplify the construction of pneumatic actions for player pianos.

Generally stated, the invention consists of a compact unit of a small number of pneumatics, preferably twelve, together with the low pressure chambers associated with these pneumatics. The invention further consists in the parts, and in the arrangements and combinations of parts which will more fully appear hereinafter.

In the accompanying drawing, which forms part of this specication, and in which like symbols refer to like parts in the several views,

Figure 1 is a top plan view of a unit pneumatic action embodying the invention, parts being broken away and shown in section; i

Fig. 2 is a rear elevation of the unit pneumatic action .shown in Fig. 1, parts being broken away and shown in section; and

Fig. 3 is a vertical transverse section on the line 3-3 in Fig. 2.

Referring to the accompanying drawing, the unit action comprises two rows or tiers of pneumatics, said rows being arranged one above the other. The construction of the pneumatics in each row is the same. The bellows 1 which operate the abstract rods of the piano action are fastened to the under-fface of a channel-board 2. The channelboard 2Y has a longitudinal channel or groove in its top face. Secured to the top face of the channel-board 2 by screws 3 is a valve-board 4. Between the valve-board 4 andthe channel-board 2 is lsuitable pack- Specication of Letters Patent.

Patented July 2, 1918.

Serial No. 867,048.

ing 5. The channel in the top face of the channel-board 2 is an air-tight low pressure chamber 6 which extends longitudinally of the unit.

In the bottom of the channel of the channel-board 2 and over each bellows 1 is a cylindrical recess or diaphragm chamber 7. Over each recess 7 is glued a diphragm 8 of sheep-skin, or other soft and flexible material. On the top face of each diaphragm 8 is fastened a small button 9 of Celluloid or like material. Extending from the bottom of each recess 7 through the front side of the channel-board 2 is ay passage 10, in

-the end of which is fixed va bent metal tube 11. To the tubes 11 are fixed the lengths of rubber tubing which connect the unit pneumatic action to the tracker-bar. Connecting each passage 1Q with the low pressure chamber G is an auxiliary passage 12. Over the upper end of the auxiliary passage 12 is glued a disk 13 of Celluloid or like material which has a pin hole through it.

Above each bellows 1 in the top face of the valve-board 4 is a cylindrical recess or valve chamber 14. A. metal tube 15 extends from the low pressure chamber 6 to the recess 14 and projects aY short distance above the bottom of said recess. In each recess 14 is a valve 16 consisting of a metal disk, having glued to its under face a thin disk 17 of soft leather or like material. To the centerof the leather disk 17 is glued a valve stem 18, which extends downwardly through the tube 15 and rests upon the sage 21 extending downwardly through the valve-board 4 and the channel-board 2.

The two rows of pneumatics are connect'- ed at one end by a board 22 which is fastened over the ends of the low pressure chambers 6. At the other end of the unit pneumatic action, the rows of pneumatics are connected by a block 23. In the block 23 is a passage 24 which connect-s the low pressure chamber 6 of the upper row and the low pressure chamber 6 of the lower row. In the block 23 is fitted a pipe 25 which communicates with the recess 24 in said block. The pipe 25 is connected by rubber tubing to the main low pressure chamber of the instrument (not shown). In order to secure the block 23 to the rows of pneumatics, so that said block maybe detached and replacedwithout impairing the .joint between said block and said rows of pneumatics, small metal blocks 26 are embedded in each channel-board 2 and in each valve-board 4 near the ends thereof. The blocks 26 have screw-threaded holes therein, which are. arranged to receive the machine screws 27 which pass through said block 23. The-board 22 is secured in a like manner. Brackets 28 are secured to the block 23 and the board 22 and provide convenient means for securing the unit pneumatic action in place in the instrument case.y

Referring to the operation of the unit pneumatic action shown and `hereinbefore described, the parts are shown in their normal position which continues as long as the music sheet covers the openings in the tracker-barV (not shown). lhen the music sheet. uncovers the openingin the trackerbar, air rushes through the'tubing to the corresponding pneumatic. Thus, outside aiirpasses through the pipe 11, and to the diaphragm chamber '7 and raises the diaphragm S. The outside air mayv also pass Ythrough the auxiliary passage 12 and through the pin hole in the disk 13 to the .low pressure chamber G, but the pin hole in said disk 13fis so small that the greater portion of the air passes into the diaphragm chamber' 7. The movement of the diaphragm V8 raises the valve 16. The valve 16S-closes the opening in the valve cap 19, thus shutting 0H communication between 'the valve chamber 14 and the outside air. VThev raising of the valve 16 also opens cominunication through the tube 15, the valve chamber 14, and the passage 21 between the -low pressure chamber 6 and the bellows `1 corresponding to the valve operated. The -air is rapidly withdrawn from theV bellows 1, andthe pressure of the outside air causes said bellows to contract and operate the ablstract rod of the pianoaction to which it is connected.

After the note has been sounded, and the music sheet has covered the hole in the tracker-bar, the air in the diaphragm chamber 7, the passage 12, the pipe 11 and the tubing connecting said pipe 11 with the tracker-bar, is drawn into the low Ypressure "chamber 6 through the pin hole in the disk --13'. -The pressure of vthe air in the dia` `ph-ragm chamber 7 being thus reduced,

the lvalve 16 drops tofits Ynormal position (as `shown Vin the drawing), this movementof the valve being aided by the-.pressure of the outside air upon the top of said valve.

7When the valve 16 is in its loweror normal position, communication between the valve chamber 14 and the low pressure chamberisclosed, and communication between the' outside air and the inside of the bellows 1 is opened. The bellows 1 assumes its normal position due to its weight and the weightof the piano action.

The pneumatic actions for player pianos were iirst constructed to soundV only sixtyve of the eighty-eight notes of the piano. Later, after the development of player piano actions which would sound all of the eighty-eight notes of the piano, the music rolls were all made to play eighty-eight notes. Attempts have been made to make the sixty-five note player actions capable 'of working with eighty-eight note music,

ited space inthe case of a piano having a siXty-ve" note player action therein, these attempts have been directed to devices for coupling the unplayed not-es of the pianos having sixty-live note player actions therein with the pneumatics of the sixty-five note player actions. The unit shown and hereinbefore described is so compact that two of them may be placed in the case of a piano having a sixty-five note player action therein and be easily connected to said sixty-live note player action by means of the pipes 25. Also, units like those shown and described can be coupledtogether to form a complete action of eighty-eight notes.

In theaction shown and hereinbefore described, the parts are easily accessible. The valve cap 19 can be .quickly removed and the Vvalve 16 adjusted or replaced. By loosening the screws 3 the valve-board 4 can be vremoved from the channel-board 2, thus and Vcan be fastened .by screws to the valve- ,Y

board 24 without danger of splitting, so that they may be easilyremoved.

That I claim as myinvention is:

1. A unit pneumatic action for mechanical pianos consisting of a plurality of pneumatics arranged in tiers, said tiers being selectively removable, and the pneumatics in each tier being secured transversely beneath a horizontal valve-block composed of top and bottom boards in continuous contact along their side margins, the bottom or channel-board having a longitudinal channel in its top face, and the top or valve-board being removably secured to the top face of said channel-board and having a series of valvevvalves mounted in said valve-chambers for operating the pneumatics in said tier and having stems projecting downwardly into said channel, and diaphragms for operating said valves secured the bottom of said channel below said valves, said valve-board and said channel-board having separately detachable end supporting means whereby they may be removed selectively and the removal of either said valve-board or said channel-board exposes all of the valve stems and diaphragms in said tier.

2. A pneumatic action for mechanical pianos comprising a horizontal channel-board having a longitudinal channel in its top face and a series of pockets in the bottom of said channel, a valve-board removably secured to the top face of said channel-board, said valve-board having recesses in its top face communicating with said channel in vertical alinement with said pockets, a valve in each recess having a stem projecting down through said valve-board, said stems positioning said valves in their recesses, annular valve caps removably secured to the top face of said valve-board over the recesses therein, and diaphragms for operating said valves secured in the pockets in the bottom of said channel, whereby said valves are separately removable from said recesses and said valve-board and valves are removable all together to expose said diaphragms, said valve-board and said channel-board having separately detachable end supporting means whereby they may be removed selectively.

3. A pneumatic action for mechanical pianos comprising a series of pneumatics, a horizontal channel-board having a longitudinal channel in its top face, a valve-board removably secured to the top face of said channel-board and carrying the air valves for said pneumatics, said channel-board having diaphragm chambers in the bottom of said channel closed by diaphragme, said in separate pockets in channel-board having passages therein eX- tcnding horizontally from Said diaphragm chambers to the outside of said channelboard, said passages communicating with said channel through restricted openings in the bottom of said channel, whereby removal of said valve-board exposes said diphragms and restricted openings, said valve-board and said channel-board having separately detachable end supporting means whereby they may be removed selectively.

4. A unit pneumatic action for mechanical pianos consisting of a plurality of pneumatics arranged in tiers, each tier comprising a channel-board and a valve-board having continuous edges detachably secured together in contact throughout their length and forming a horizontal low pressure chamber between them, said valve-board having recesses in its top face which constitute valve chambers, single disk valves mounted in said valve chambers and having leather facings on their under sides, annular valve caps removably secured over said recesses and having leather seats on their under sides, said channel-board having recesses therein which constitute diaphragm chambers, bleeder ducts connecting said diaphragm chambers and low pressure chamber, and diaphragms for operating said valves secured over said last-mentioned recesses, whereby removal of said valve board exposes all of said valve stems, bleeder ducts and diaphragme, each of said valve-boards and channel-boards having separately detachable end supporting means whereby each one of them mau be removed independently of the others.

Signed at St. Louis, Missouri, this 13th day of October, 1914.

HARRY MEYER.

Witnesses:

NE1L D. PRESTON, MARTHA A. SHEL'roN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Wnhinmmn." 

